WI-LAN Inc. v. Alcatel-Lucent USA Inc. et al

Filing 182

REPLY to 167 Claim Construction Brief,,,,, filed by WI-LAN Inc.. (Attachments: # 1 Affidavit Declaration of Jeffrey T. Han, # 2 Exhibit I - true and correct copy of U.S. Patent No. 5,603,095, # 3 Exhibit II - true and correct copy of U.S. Patent No. 5,239,682, # 4 Exhibit III - true and correct copy of U.S. Patent No. 5,659,598., # 5 Exhibit IV - true and correct copy of WO 96/37054., # 6 Exhibit V - true and correct copy of Sanford Bingham, Multiplexers, Computerworld, Nov. 27, 1989, at 61., # 7 Exhibit VI - true and correct copy of David J. Stang, Network)(Weaver, David)

EXHIBIT I

111111111111111111111111111111111111111111111111111111111111111111111111111
US005603095A

United States Patent

[11]

Uola
[54]

Inventor:

Date of Patent:

5,142,563
5,392,462

RADIO SYSTEM AND A SUBSCRffiER
TERMINAL FOR A RADIO SYSTEM

[75]

Assignee: Nokia Telecommunications Oy, Espoo,
Finland

[21]

App!. No.:

436,468

[22]

PCT Filed:

Sep. 27, 1994

[86]

PCT No.:

PCTIFI94/00436

§ 371 Date:

May 26,1995

PCT Pub. No.: W095/09512
PCT Pub. Date: Apr. 6, 1995
Foreign Application Priority Data

Sep. 27, 1993
[51]
[52]
[58]

[FI]

Finland .................................... 934232

6

Int Cl. .•.......•.•.................. H04B 7/26; H04B 17/00
U.S. CI•....................... 455/67.1; 455/54.1; 455/67.7;
4551127; 455/343; 379/58; 340/539; 340/636
Field of Search .................................. 455/67.1,67.7,
4551127,343,54.1,33.1,89, 88, 115; 379/58,
61; 340/531, 539, 636
References Cited

[56]

u.s.
4,367,458

0542509
0544635

811992 Nyuu et al. .
2f1995 Komaki ..................................... 379/61

PATENT DOCUMENTS

111983 Hackett ................................... 340(531

5f1993
6f1993

European Pat Ofr .
European Pat Off..

Primary Examiner-Chi H. Pham
Attorney, Agent, or Finn-Cushman Darby & Cushman IP
Group of Pillsbury Madison & Sutro LLP
[57]

§ 102(e) Date: May 26,1995

[30]

Feb. 11, 1997

FOREIGN PATENT DOCUMENTS

Risto Uola, Oulu, Finland

[73]

[87]

5,603,095

Patent Number:

[45]

[19]

ABSTRACT

A radio system providing a wireless local loop, including a
fixed network having at least one exchange, at least one
subscriber database and base stations, and subscriber terminals communicating with the fixed network via a radio path.
Each subscriber terminal includes a radio transceiver, a
power source with a battery backup unit, a measurer for
measuring the signal level and signal quality on the radio
path between a base station and the subscriber terminal, and
a measurer for measuring the charge level of the battery
backup unit of the power source. The subscriber terminal
transmits the test results concerning at least one of the
battery backup unit and the power supply to the fixed
network in a predetermined report message at predetermined
intervals or in response to a predetermined test result. The at
least one subscriber database of the radio network maintains
information about at least one of the charge levels of the
batteries and failures in the power supply of the subscriber
terminals, and about the signal level and signal quality
measured by the subscriber terminal.
14 Claims, 2 Drawing Sheets

19

18

~'4

MSC

13

~ @

15
A-ID

12

WIL-0192825

u.s. Patent

Feb. 11, 1997

Sheet 1 of 2

5,603,095

u

1Il

CD

WIL-0192826

u.s. Patent

Feb. 11, 1997

26

10

-r

25

SPEECH
CODER

CHANNEL
DECODER

5,603,095

Sheet 2 of 2

23

24

21

22

DElNTERLEAVING

I

DETECTOR

AID

Q

Rx
ANT 3

3

PS
28

TCNA

SPEECH
CODER

CHANNEL
CODER

INTERAVING

BURST
ORMATION

MOD

34

33

32

31

30

1

Tx

Q

29

FIG. 2

Bit

8

7

6

5

4

3

2

1

A

0

0

0

0

0

1

0

1

8

0

X

1

1

0

0

1

0

Length

C

o

0

0

C1 low

E

0

0

DSC low

F

Length

G

Alarm status

H

Charge level

FIG. 3

WIL-0192827

5,603,095

2

1
RADIO SYSTEM AND A SUBSCRIBER
TERMINAL FOR A RADIO SYSTEM
FIELD OF THE INVENTION

5

The invention relates to a radio system providing a
wireless local loop, the system comprising a fixed network
including at least one exchange, at least one subscriber
database and base stations, and subscriber terminals com10
municating with the fixed network via a radio path, each
subscriber terminal comprising a radio transceiver, a power
source with a battery backup unit, means for measuring the
signal level and signal quality on the radio path between a
base station and the subscriber terminal, and means for
15
measuring the charge level of the battery backup unit of the
power source.
BACKGROUND OF THE INVENTION
20

Thc most expensive and the most time-consuming part in
setting up conventional cable-based telecommunication networks is cabling, which connects each subscriber to the local
cxchange. In many cases it is preferable to replace fixed
subscriber cables with a radio connection which can be
established easily and quickly to connect the subscribers to
the public switched telephone network (PSTN) in areas
where no subscriber lines are available and it is too expensive, too slow or otherwise impractical to install them. Thus
the subscriber network comprises, in the same way as a
normal mobile telephone network, base stations connected
to the exchange, the subscriber terminals (mobile telephones) having a radio connection with the base stations.
Such a system is called a wireless local loop (WLL). Since
a WLL radio system is generally an extension of the normal
public switched telephone network, it typically uses the
normal numbering of a phone network. Alternatively, it is
possible to use the numbering of a mobile telephone network. A call to the phone number of a WLL subscriber
generally causes the routing of the call always to one and the
same exchange and base station connected to it, the base
station paging the subscriber via a radio path. It is possible
to connect any conventional telephone set to the WLL radio
system, and thus the radio path is invisible to the user and
provides, through the base station, a point-to-point connection between the WLL telephone set and the exchange.
The WLL network opcrator is usually responsible for the
equipment at both ends of the radio path. The base station
equipment is connected directly to the network and thus it is
relati vely easy to monitor. However, the operator should also
be able to monitor the subscriber terminal at the other end of
the radio path. If the level or quality of the signal received
by the subscribcr terminal is too low, the quality of the call
is poor or calls to the subscriber terminal will be completely
prevented. This corresponds to a poor or a disconnected
subscriber line in a fixed network. In addition, in WLL
applications the operator cannot provide power supply for
the subscriber terminal through the subscriber line as in a
cabled phonc network, but the power supply has to be
organized locally in the location of the subscriber terminal.
This means that the subscriber terminal has to be provided
with a battery backup unit to ensure the connection in all
situations, for example during a power failure. Therefore, it
should be possible to monitor also the power supply of the
subscriber terminal, the charge level of the battery backup
unit and preferably also any malfunctions related to the
supply of charging current.

25

30

Mobile telephones for conventional mobile telephone
networks conduct, in an idle state, some kind of measurements on the received signal level and quality of the radio
channel. A typical mobile telephone also measures the
charge level of the battery. These measurements are conducted, however, only for the user of the mobile telephone,
who is responsible for the condition of his own mobile
telephone in a conventional mobile phone network. The
measured information is shown to the user on the display of
the mobile telephone, and if some failure is detected, the
user is alarmed. U.S. Pat. No. 5,142,563 discloses a similar
application, where the portable part of a wireless telephone
monitors the voltage level of its battery power source, and
when the voltage level drops, sends a signal to the fixed part,
the so-called base station, of the wireless telephone, the
signal directing the base station to a quick-charging state to
wait for the wireless telephone to be positioned on the
charging device of the base station. The base station is meant
to be connected to a normal subscriber line of a wired
telephone network. The operator of a conventional mobile
telephone network or a fixed network is not responsible,
however, for the working condition of the wireless terminal
equipment or the mobile telephone of the subscriber, but,
instead, what is provided is only a local indication about the
condition of the terminal equipment, given to the user or
intended for the internal use of the terminal equipment. Such
a local indication is not suitable, however, for the operator
of a WLL network, since its utilization would require
repeated visits to the mobile telephone or the wireless
telephone, and would thus be extremely difficult and would
mean long intervals between the checks. The operator of a
WLL network needs such information centralized in one
place, so that the operator could control the accessibility of
the network and the need for maintenance.

35

SUMMARY OF THE INVENTION
The object of the invention is a radio system providing a
wireless local loop and collecting the aforementioned infor40 mation.
This object is achieved by means of a radio system similar
to the one described in the introductory paragraph, the
system being characterized according to the invention in that
the subscriber terminal transmits the test results concerning
45 the battery backup unit and/or the state of the power supply
to the fixed network in a predetermined report message at
predetermined intervals or in response to a predetermined
test result, and that the at least one subscriber database of the
radio network maintains information about the state of the
50 power supply of the subscriber terminals and/or the charge
levels of the batteries, and about the signal level and signal
quality measured by the subscriber terminal.
According to the invention, the subscriber terminal
reports the test results concerning the power supply and/or
55 the battery backup unit and the level and quality of the
received signal to the network in a special test report
message. This message can be transmitted whenever a
signalling connection is established, at suitable intervals and
in special situations. The test report messages are used for
60 updating the subscriber database of the fixed network, the
database containing information about the state of the power
supply of the subscriber terminals and/or the charge levels of
the battery backup units and about the signal level and
quality measured by the subscriber terminal in order to
65 detect malfunctions concerning the battery backup unit. If,
for example, reports about a break in the charging current of
the battery backup unit are desired from subscriber termi-

WIL-0192828

5,603,095

3

4

explained by using as an example the application of a WLL
network in the Pan-European mobile phone network GSM,
without restricting the invention, however, thereto.
The radio system shown in FIG. 1 comprises an exchange
MSC, a base station controller BSC, a number of base
stations BTS and a large number of subscriber terminals SE.
In the same way as a conventional mobile exchange, the
exchange MSC comprises a switch for connecting calls, and
a call control computer, which controls all signalling
between the subscriber terminals and the radio network
when a call is established, during the call and when it is
ended, and which allocates radio channels for the calls, for
the radio connections between a base station BTS and
subscriber terminals SE. The exchange MSC of the radio
system also has a connection 15 to a public switched
telephone network PSTN 12 and, through that, to PSTN
subscribers 11 or to other networks 22 and their subscribers.
The base station BTS can also be realized in the same way
as a base station of a conventional mobile telephone system,
but its basic units are naturally a set of transceivers, the exact
number of which is determined by the traffic capacity
requirements.
A WLL subscriber terminal SE typically comprises a
mobile telephone unit 13 and a conventional telephone set
14. The mobile telephone unit operates as an interface unit
to the radio path and provides the user with a normal
subscriber line, to which the user can connect his conventional telephone set 14. However, the subscriber terminal
can also be a portable mobile telephone, as will be explained
below in connection with FIG. 2.
In WLL radio systems, the exchange MSC makes a fixed
association between the telephone number of a subscriber
terminal and a subscriber terminal SE located in the location
area formed by one particular base station BTS or by several
base stations. When there is a call to the telephone number,
the exchange MSC starts paging for the subscriber terminal
in the area of the base station BTS indicated by the telephone
number or in the location area containing several base
stations. Since the location of the subscriber is assumed to
be fairly permanent, mobility management functions and
location updating are not necessarily needed in the radio
system. However, there is at least one subscriber database in
BRIEF DESCRIPTION OF THE DRAWINGS
the radio system, for example a visitor location register VLR
The invention will be described by means of illustrative
45 associated with the exchange MSC, the VLR maintaining
embodiments, with reference to the accompanying drawinformation about the subscribers in the area of the
ings, in which:
exchange, or a home location register HLR, where informaFIG. 1 represents a radio system according to the invenlion about the subscribers in the entire network is centraltion, and
ized.
FIG. 2 is a block diagram of a subscriber terminal 50
FIG. 2 shows a mobile telephone applicable as a subaccording to the invention, and
scriber terminal SE according to the invention. The SE
comprises an antenna 3, a duplex filter 28, a receiver 21, a
FIG. 3 represents a test report message applicable in the
transmitter 29 and a synthesizer 27. In the receiving direcGSM system.
tion, an ND converter 22, a detector 23, a de-interleaver 24,
55 a channel decoder 25, a speech coder 26 and a loudspeaker
PREFERRED EMBODIMENTS OF THE
are connected in series with the receiver 21. In the transINVENTION
mitting direction, a modulator 30, TDMA burst formation
31, an interleaver 32, a channel coder 33, a speech coder 34
The present invention can be applied in any radio system
and a microphone are connected in series in front of the
which is used as a wireless local loop (WLL) to replace the
cabled subscriber lines between a fixed network and the 60 transmitter. All the aforementioned blocks are controlled by
a timing and control unit 35, which handles all outbound and
subscribers. FIG. 1 shows a general view of one cellular
inbound messages. The power source 3 forms the operating
radio system, according to the invention, which is based on
the utilization of known radio networks, such as the GSM.
voltage Vee for the entire subscriber terminal from an
external power source, such as supply voltage provided by
A WLL network can even be realized as part of a conventional mobile telephone network, in which case there are 65 the mains (Le., electrical utility service line voltage) a solar
both WLL subscribers and mobile telephone subscribers in
cell or an aggregate, or from the voltage of a battery 10
the same network. In the following, the invention will be
operating as a backup power source. The power source 3

nals, the invention provides a method which prevents overloading of the network as a result of a general power failure,
but which ensures transmission of the desired information
about an individual break in the charging current before the
battery backup unit will be used up.
5
The combined processing of information concerning both
the battery backup unit and the quality of the connection can
provide, in some situations, essential information in a WLL
system. Such a situation may occur, for example, when
power supply is provided by different methods at different 10
times, for example by an aggregate and by solar cells.
Equipment malfunctions possibly caused by an individual
method are discovered, if the reports giving information
about the bad quality of a connection always include a part
15
identifying the specific power supply method.
The test results can be sent to the fixed network at
predetermined intervals under the control of a timer. The
timer is preferably a periodic location updating timer, and
the test report message is always transmitted during this
procedure. In a WLL network, where the subscriber termi- 20
nals are positioned in fixed locations, it is not necessary to
use any kind of periodic location updating procedure; however, it is advantageous to utilize this procedure for the
control procedure according to the invention. Thus, it is
possible to exploit, with slight modifications, the location 25
updating characteristics provided in the present subscriber
terminals and radio networks. The network operator can
control the interval between two successive test report
messages in an idle state by means of a periodic location
updating timer arrangement.
30
In addition to periodic reporting, test report messages can
be transmitted in response to predetermined test results. If
the status of the battery changes during a call, the test report
message is transmitted immediately. If the status changes or 35
the radio path measurements indieatc faulty conditions in an
idle state, the test report message is transmitted when the
next signalling connection is established. The subscriber
terminal which indicates a failure in the battery can also start
the location updating procedure to inform the network about 40
the failure.

WIL-0192829

5,603,095

5
also operates as the charging device for the battery 10 when
the external power source is connected. The power source 3
continuously measures the charge level of the battery 10, its
charging current andior the state of an external power source
2, and reports the test res ult to the control unit 35. The
receiver 21 measures the level of the signal received from
the base station through the radio path and reports the test
results to the control unit 35. The channel decoder 25
measures the signal quality of the control channel of the base
station by means of, for example, the number of lost 10
information blocks and reports the test result to the control
unit 35. The control unit 35 collects and analyzes the test
results. The control unit 35 can possibly show the test results
for the user on the display (not shown in the Figure) of the
subscriber terminal, and if some failure or malfunction is
15
detected, it can alarm the user.
According to the invention, the subscriber terminal
reports the test results to the fixed network in a special
message, hereafter called a test report message. This message can be transmitted whenever a signalling connection is
established between a subscriber terminal and the base 20
station. If the control unit 35 detects a change in the status
of the battery 10, a break in the charging current of the
battery andior a failure in the external power supply during
a call, it immediately generates and transmits a tcst rcport
message. If the status of the battery changes, its charging 25
current breaks andior if there is a failure in the external
power supply or if the measurements on the radio path
indicate a malfunction when the subscriber terminal is in an
idle state, the control unit 35 generates and transmits a test
report message when the next signalling connection is 30
established. Under normal circumstances, the subscriber
terminal transmits the test results to the fixed network at
predetermined intervals. For this purpose, the control unit 35
of the subscriber terminal comprises a special timer; expiring of the timer initiates transmission of a new test report
message. This timer is preferably a periodic location updat- 35
ing timer of a subscriber terminal, in which case a test report
is always transmitted during a location updating procedure,
when the timer reaches the predetermined time. A WLL
network, where the subscriber terminals are in fixed locations, does not necessarily require the use of any kind of 40
periodic location updating procedure, but the functions of
this procedure can be used for the reporting according to the
invention.
The base station BTS receives the test report messagcs
transmitted by the subscriber terminal SE and forwards them 45
to the exchange MSC, which forwards the test results to the
subscriber database of the network, for example to a visitor
location register VLR. The visitor location register VLR
maintains information about the charge levels of the batteries of the subscriber terminals, the status of their charging 50
current andior failures in the external power supply, and
about the signal level and signal quality measured by the
subscriber terminal. This information can be maintained
advantageously by the same mechanism as the location data
of a normal mobile telephone subscriber. AdvantageOUSly, 55
the test results can also be forwarded to the operation and
maintenance center OMC of the radio network. The VLR
also comprises a timer, preferably a periodic location updating timer, which controls the time that elapses in an idle state
between two successive test report messages transmitted by 60
the subscriber terminal. If no test report message is received
within a predetermined time after the previous report message, the VLR assumes that there is a failure in the subscriber terminal or it is disconnected.
FIG. 3 represents a test report message applicable in the 65
GSM system. The informaLion elements of the message,
beginning from the first line, are:

6
line A: transaction identifier and protocol discriminator;
lines C, D, E: test results of the radio path; in line C the
length of the information element (Length), in line D
the lowest received power level during a test period (C1
low), in line E the lowest value describing the signal
quality (e.g., Downlink signalling radio counter DSC)
during a test period (DSC low);
lines F, G and H contain the test results concerning the
battery unit. Line F contains the length of the information element (Length); line G, the status of the battery
(Alarm status); line H, the current charge level of the
battery (Charge level).
The figures and the description related thereto are only
meant to illustrate the present invention. The details of the
radio system and subscriber terminal according to the invention can vary within the scope of the appended claims.
I claim:
1. A radio system providing a wireless local loop, said
system comprising:
a fixed network including
at least one exchange,
at least one subscriber database, and
base stations, and
subscriber terminals communicating with the fixed network via a radio path, each subscriber terminal comprising a radio transceiver, a power source connected to
an external power supply, a battery backup unit for the
power source, means for measuring and providing test
results concerning the signal level and signal quality on
the radio path between a base station and the subscriber
terminal, and means for measuring and providing test
results concerning the charge level of the battery
backup unit of the power source,
each subscriber terminal being arranged to transmit the
test results concerning at least one of the battery backup
unit and the stale of the power supply, to the fixed
network, in a predetermined report message at predetermined intervals or in response to a predetermined
test result,
said at least one subscriber database of the radio network
being arranged to maintain information about at least
one of the charge level of the battery backup unit and
the state of the external power supply, and abut the
signal level and signal quality measured by each
respecti ve subscriber terminal.
2. A radio system according to claim 1, wherein:
each subscriber terminal comprises a timer device which
is arranged to initiate transmission of said test results to
said fixed network at predetermined intervals.
3. A radio system according to claim 2, wherein:
said fixed network comprises a timer device which is
arranged to measure the interval between successive
transmissions of report messages from each respective
subscriber terminal.
4. A radio system according to claim 2, wherein:
said timer device is a periodic location updating timer, and
each subscriber terminal is arranged to transmit said
report message during the location updating procedure.
5. A radio system according to claim 3, whercin:
said timer device is a periodic location updating timer, and
each subscriber terminal is arranged to transmit said
report message during the location updating procedure.
6. A radio system according to claim 1, wherein:
each said subscriber terminal comprises means for assessing the test results and for transmitting the test results

WIL-0192830

5,603,095
7
to the fixed network immediately after a respective next
signalling connection has been established, if the
respective test results show an essential change in the
charge level of the respective battery backup unit, at
least one of a break in its charging current and a failure 5
in the respective external power supply, or a change in
the condition of the respective radio path.
7. A radio system according to claim 1, wherein:
each subscriber terminal is arranged to cause each report
message to contain the lowest signal level measured by 10
the respective said measuring means during a respective test period, the lowest signal quality measured by
the respective said measuring means during the rcspective test period and the current charge level of the
15
respective battery backup unit.
8. A radio system according to claim 1, wherein:
said external power supply includes mains voltage, a solar
cell, or an aggregate of mains voltage and a solar celL
9. A subscriber terminal for a radio system providing a
wireless local loop, the system comprising a fixed network 20
including at least one exchange, at least one subscriber
database and base stations, said subscriber terminal communicating via a radio path with the fixed network and
comprising:
25
a radio transceiver,
a power source connected to an external power supply,
a battery backup unit for said power source,
means for measuring the signal level and signal quality on
the radio path between a respective one of said base 30
stations and said subscriber terminal, and means for
measuring the charge level of said battery backup unit,

8
the subscriber terminal being arranged to transmit test
results concerning at least one of said battery backup
unit and said external power supply, to said fixed
network, in a predetermined report message at predetermined intervals, or in response to a predetermined
test result.
10. A subscriber terminal according to claim 9, further
comprising:
a timer device which initiates transmission of said test
results to said fixed network at predetermined intervals.
11. A subscriber terminal according to claim 10, wherein:
said timer device is a periodic location updating timer, and
that said subscriber is arranged to transmit said report
message during a location updating procedure.
12. A subscriber terminal according to claim 9, further
comprising:
means for assessing the test results and for transmitting
the test results to said fixed network immediately if the
test results show an essential change in the charge level
of the battery backup unit or in the condition of the
radio path.
13. A subscriber terminal according to claim 9, wherein
the report message contains the lowest signal level measured
during a respective test period, the lowest signal quality
measured during the respective test period, and the current
charge level of the battery backup unit.
14. A subscriber terminal according to claim 8, wherein:
said external power supply includes mains voltage, a solar
cell, or an aggregate of mains voltage and a solar cell.

* * * * *

WIL-0192831